/*
    main.cpp
    Copyright (C) 2008-2009 somebody
    Copyright (C) 2009 yellow wood goblin

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program. If not, see <http://www.gnu.org/licenses/>.
*/

#include <nds.h>
#include <string.h>
#include "../../share/fifotool.h"
#include "../../share/memtool.h"

#ifdef __cplusplus
extern "C" {
#endif
void __libnds_exit(int rc) {}
#ifdef __cplusplus
}
#endif

void VblankHandler(void)
{
  inputGetAndSend();
}

#define PM_NDSLITE_ADR (4)
#define PM_CONTROL2_REG (16)
#define PM_CONTROL2_RESET (1)
#define PM_NDSLITE_ISLITE BIT(6)
#define PM_NDSLITE_BRIGHTNESS(x) ((x&0x03)<<0)
#define PM_NDSLITE_BRIGHTNESS_MASK (PM_NDSLITE_BRIGHTNESS(3))

static u32 getSystem(void)
{
  static u32 dsGen=0;
  if(!dsGen)
  {
    dsGen=1; // default ds phat
    if(readPowerManagement(PM_NDSLITE_ADR)&PM_NDSLITE_ISLITE) dsGen++; // dslite and dsi
    if(readPowerManagement(PM_NDSLITE_ADR)==readPowerManagement(5)) dsGen++; // dslite
  }
  return dsGen;
}

static void prepairReset()
{
  //enable sound
  if(2==getSystem()) writePowerManagement(PM_CONTROL_REG,(readPowerManagement(PM_CONTROL_REG)&~PM_SOUND_MUTE)|PM_SOUND_AMP);

  //disble rtc irq, on some games enabled rtc irq caused tearing.
  uint8 command[2];
  command[0]=WRITE_STATUS_REG2;
  command[1]=0x00;
  rtcTransaction(command,2,0,0);

  REG_POWERCNT|=POWER_SOUND;

  //reset DMA
  zeroMemory((void *)0x40000B0,0x30);

  REG_IME=IME_DISABLE;
  REG_IE=0;
  REG_IF=~0;

  fifoSendValue32(FIFO_USER_01,MENU_MSG_ARM7_READY_BOOT);
  swiDelay(1);
}

static void brightnessNext(void)
{
  u8 data=readPowerManagement(PM_NDSLITE_ADR);
  if(0==(data&PM_NDSLITE_ISLITE)) // this is not a DS Lite machine
    return;
  u8 level=data&PM_NDSLITE_BRIGHTNESS_MASK;
  level++;
  data&=~PM_NDSLITE_BRIGHTNESS_MASK;
  data|=PM_NDSLITE_BRIGHTNESS(level);
  writePowerManagement(PM_NDSLITE_ADR,data);
}

static void brightnessSet(u8 level)
{
  u8 data=readPowerManagement(PM_NDSLITE_ADR);
  if(0==(data&PM_NDSLITE_ISLITE)) // this is not a DS Lite machine
    return;
  data&=~PM_NDSLITE_BRIGHTNESS_MASK;
  data|=PM_NDSLITE_BRIGHTNESS(level);
  writePowerManagement(PM_NDSLITE_ADR,data);
}
static u8 brightnessGet(void)
{
  u8 data=readPowerManagement(PM_NDSLITE_ADR);
  if(0==(data&PM_NDSLITE_ISLITE)) // this is not a DS Lite machine
    return 0;
  return data&PM_NDSLITE_BRIGHTNESS_MASK;
}

static void menuValue32Handler(u32 value,void* data)
{
  switch(value)
  {
    case MENU_MSG_GBA:
      {
        u32 ii=0;
        if(PersonalData->gbaScreen)
          ii=(1*PM_BACKLIGHT_BOTTOM)|PM_SOUND_AMP;
        else
          ii=(1*PM_BACKLIGHT_TOP)|PM_SOUND_AMP;
        writePowerManagement(PM_CONTROL_REG,ii);
        swiChangeSoundBias(0,0x400);
        swiSwitchToGBAMode();
      }
      break;
    case MENU_MSG_ARM7_REBOOT:
      prepairReset();
      swiSoftReset();
      break;
    case MENU_MSG_BRIGHTNESS_NEXT:
      brightnessNext();
      break;
    case MENU_MSG_SYSTEM:
      fifoSendValue32(FIFO_USER_02,getSystem());
      break;
    case MENU_MSG_BRIGHTNESS_GET:
      fifoSendValue32(FIFO_USER_01,brightnessGet());
      break;
    case MENU_MSG_BRIGHTNESS_SET0:
    case MENU_MSG_BRIGHTNESS_SET1:
    case MENU_MSG_BRIGHTNESS_SET2:
    case MENU_MSG_BRIGHTNESS_SET3:
      brightnessSet(value&3);
      break;
    case MENU_MSG_SHUTDOWN:
      if(2==getSystem()) writePowerManagement(PM_CONTROL2_REG,readPowerManagement(PM_CONTROL2_REG)|PM_CONTROL2_RESET);
      else systemShutDown();
    default:
      break;
  }
}

int main()
{
  //mute sound
  if(2==getSystem()) writePowerManagement(PM_CONTROL_REG,(readPowerManagement(PM_CONTROL_REG)&~PM_SOUND_AMP)|PM_SOUND_MUTE);
  //switch on backlight on both screens
  writePowerManagement(PM_CONTROL_REG,readPowerManagement(PM_CONTROL_REG)|PM_BACKLIGHT_BOTTOM|PM_BACKLIGHT_TOP);

  // read User Settings from firmware
  readUserSettings();

  irqInit();
  fifoInit();

  // Start the RTC tracking IRQ
  initClockIRQ();

  fifoSetValue32Handler(FIFO_USER_01,menuValue32Handler,0);

  installSystemFIFO();

  irqSet(IRQ_VBLANK,VblankHandler);

  irqEnable(IRQ_VBLANK|IRQ_NETWORK);

  while(true) swiWaitForVBlank();
}